Hi, I’m Carol. Today I’ll be taking you through the lessons Population Circle and Oh How We’ve Grown, lessons that look at how the global population has changed over the past 500 years. There is significant overlap between these two lessons.
Oh How We’ve Grown is a two-part lesson and Population Circle actually serves as part 1, as well as being its own standalone lesson plan.
These lessons cover topics that are great for social studies, but they can also be plugged into science and math. And though written for middle level or upper elementary grades, the content is relevant to some high school classes and can be fun at that level as well.
There are two matching objectives in these lessons. First, that students will be able to describe trends of human population growth. And second, explain the basic attributes of exponential growth (slow start, fast finish). From Part 2 of Oh How We’ve Grown, students will be able to prepare a timeline that graphically portrays population doubling through history.
Let’s get started with Population Circle.
Population Circle/Part 1 of Oh How We’ve Grown
To prepare for this interactive activity, you’ll put a large circle of yarn on the ground and cut out the 32 counting cards provided in the lesson plan. I’ll narrate as I would in class:
The circle of yarn represents the Earth. And today, we’re going to travel through time to experience how the population of the Earth has changed over 500 years. The way that we travel through time is by counting. We’ll count from 1 to 100 and with each number, jump through time 5 years. When we begin, and are at zero, the year is 1525.
So when we count 1, we’ll be in 1530. When we count 2 we’ll be in 1535. 3 – 1540. And so on so that when we say 100 we’ll be in the year 2025.
Each student receives a counting card. The card has two numbers, and for the simulation, we’ll focus on the number right in the middle, that’s between 0 and 100. As we count, when we say the number on anyone’s card, that person steps into the yarn circle. And by doing so, they have just added to the global population.
To demonstrate today, I’m simply going to use this small circle of yarn on the table. And rather than students stepping into it, I’ll be placing the cards themselves within the circle to represent population growth.
Now, there are two cards with zero. Those two students should step into the circle before the counting begins, to represent the population in the year 1525.
After that the counting begins, with students stepping into the circle at the appropriate time.
1, 2, 3, 4,… 100. Welcome to the year 2025!
At the end of the simulation, I really like to ask students to describe, in their own words, what they saw happen. For scaffolding, you may first ask students to literally describe what they saw – so speaking in terms of their classmates, counting, and a circle of yarn. After they’ve described the concrete, they can describe what the simulation represents – so now speaking in terms of the global population on the Earth over several hundred years.
And that’s the lesson Population Circle, and Part 1 of Oh How We’ve Grown.
Part 2 of Oh How We’ve Grown
Now I’d like to show you Part 2 of the lesson Oh How We’ve Grown.
Here we’ll again look at 500 years of population history, but by creating a timeline and specifically considering doubling time.
The timeline will be created by using length to represent time. The scale is 1 meter = 100 years. If you’d like to have students practice linear metric measurements, you could break this down to decimeters and centimeters as well.
Display the chart of World Population Growth Doubling Time from the lesson plan. Students will first determine how many years it took for the population to double starting in 1525. Then they’ll convert those years into length.
For example, the population of 500 million in 1525 doubled to 1 billion in 1804. That took 279 years. Using our scale of 100 years = 1 meter, I calculate that this section of the timeline should be 2 meters and 79 centimeters long.
Now it’s time to build the timeline! Students will start with the year 1525 represented at one end of paper on a roll of adding machine tape. They’ll measure the appropriate length to represent the first doubling of global population. Then the second doubling. And so on.
Check out the lesson plan for discussion questions that can help you debrief both the simulation and timeline with students. We also provide some critical thinking questions, asking students what changed in the past 500 years that could’ve impacted how our population grew, and what would happen if we continue to grow at the current rate.
And that’s a wrap! I hope you’ll try out Population Circle or Oh How We’ve Grown with your students. If you’d like to find more lessons about demographics or other population-related content, please visit our website at PopulationEducation.org.